Interactive input systems that allow users to inject input into an application program using an active pointer (eg. a pointer that emits light, sound or other signal), a passive pointer (eg. a finger, cylinder or other object) or other suitable input device such as for example, a mouse or trackball, are well known. These interactive input systems include but are not limited to: touch systems comprising touch panels employing analog resistive or machine vision technology to register pointer input such as those disclosed in U.S. Pat. Nos. 5,448,263; 6,141,000; 6,337,681; 6,747,636; 6,803,906; 7,232,986; 7,236,162; and 7,274,356 and in U.S. Patent Application Publication No. 2004/0179001 assigned to SMART Technologies ULC of Calgary, Alberta, Canada, assignee of the subject application, the entire disclosures of which are incorporated by reference; touch systems comprising touch panels employing electromagnetic, capacitive, acoustic or other technologies to register pointer input; tablet and laptop personal computers (PCs); smartphones, personal digital assistants (PDAs) and other handheld devices; and other similar devices.
Above-incorporated U.S. Pat. No. 6,803,906 to Morrison et al. discloses a touch system that employs machine vision to detect pointer interaction with a touch surface on which a computer-generated image is presented. A rectangular bezel or frame surrounds the touch surface and supports digital cameras at its corners. The digital cameras have overlapping fields of view that encompass and look generally across the touch surface. The digital cameras acquire images looking across the touch surface from different vantages and generate image data. Image data acquired by the digital cameras is processed by on-board digital signal processors to determine if a pointer exists in the captured image data. When it is determined that a pointer exists in the captured image data, the digital signal processors convey pointer characteristic data to a master controller, which in turn processes the pointer characteristic data to determine the location of the pointer in (x,y) coordinates relative to the touch surface using triangulation. The pointer coordinates are conveyed to a computer executing one or more application programs. The computer uses the pointer coordinates to update the computer-generated image that is presented on the touch surface. Pointer contacts on the touch surface can therefore be recorded as writing or drawing or used to control execution of application programs executed by the computer.
International PCT Patent Application Publication No. WO 2010/028490 to McGibney et al., assigned to SMART Technologies ULC, discloses a touch input system comprising at least two imaging assemblies capturing image frames of a region of interest from different vantages. Each imaging assembly comprises an image sensor and integrated signal processing circuitry. The integrated signal processing circuitry is implemented on a field programmable gate array (FPGA), a digital signal processor (DSP) or an application specific integrated circuit (ASIC). The integrated signal processing circuitry comprises a spotlight processor and a bezel processor to pre-process image data acquired by the associated image sensor and generate pointer data, and pointer hover and contact status data.
Although a variety of interactive input system exists, in many cases, the interactive input systems employ off-the shelf components. Unfortunately, these off-the-shelf components tend to be large in size, expensive and power inefficient. This of course increases interactive input system manufacturing and operating costs. In addition, in interactive input systems employing multiple processors that communicate over communication links, the designs of the processor circuitry and communication links have limited processing and communication speed causing latency issues. As will be appreciated, improvements in interactive input system design are desired.
It is therefore an object of the present invention to provide a novel interactive input system and method and a novel imaging assembly therefor.